Not a simple trip from here, but good to know and plan for. Apparently Yellowstone opens the roads to cyclists early April until late April (21st this year): http://www.npr.org/2017/04/02/522326...in-yellowstone
at least I assume this is an annual thing. I thought some folks might be interested for future planning. Many of us here would be prepared for the possible weather they could have. I am not sure about the bears, however.